Switch actuator mechanism



Nov. 23, 1965 s. YERKOVICH 3,219,775

SWITCH ACTUATOR MECHANISM Filed Dec. 5, 1950 2 Sheets-Sheet l Fig. 1

WITNESSES INVENTOR.

Simon Yerkovich flu/M 6. WW BY Nov. 23, 1965 s. YERKOVICH 3,219,776

SWITCH ACTUATOR MECHANISM Filed Dec. 5, 1950 2 Sheets-Sheet 2 & 1Q ss Fig. 4

Fig. 2

WITNESSES INVENTOR.

Simon Yerkovich 20M C. WM BY United States Patent 3,219,776 SWITCH ACTUATOR MECHANISM Simon Yerkovich, Los Angeles, Calif., assignor, by mesne assignments, to the United States of America as represented by the United States Atomic Energy Commission Filed Dec. 5, 1950, Ser. No. 199,301 (Iiaims. (Cl. 20077) This invention relates to an automatically operated snap acting switch and is particularly concerned with a type of mechanism adapted to be constructed in small compact form and to provide for a predetermined amount of pre-travel and over-travel of the switch actuator. The switch may have various applications and uses; however, a preferred application of the switch has been found to reside in a type of adaptation wherein the switch automatically operates to closed position of its contacts upon the withdrawal or removal of a wire, pin, or similar equivalent control instrnmentality. More specifically the invention has found notable utility as a circuit arming device in bombs which are dropped from aircraft and, of course, it could be utilized as an arming device in related types of weapons.

In connection with the pre-travel and over-travel characteristics of the switch mechanism it embodies snap acting movements including arrangements whereby the snap acting mechanism passes over center position and in so doing the mechanism engages or, that is, picks up a contact actuating member which performs the actual contacting operation.

The snap acting mechanism is of the type employing a spring detent and the contact actuating member frictionally engages a contactor providing an arrangement having substantial shock and vibration resistant characteristics but, nevertheless, providing for ease of assembly and disassembly.

The primary object of the invention is to provide an effective snap acting switch having predetermined pretravel and over-travel characteristics with reference to the operating member.

Another object of the invention is to provide a snap acting switch mechanism comprising a snap acting mechanism, an operating member engageable with the snap acting mechanism through a lost-motion connection, the snap acting mechanism being normally biased to one of its operating positions.

Another object of the invention is to provide a snap acting switch mechanism comprising a plunger having a sleeve mounted thereon, spring detent mechanism cooperating with the sleeve whereby the sleeve is movable with a snap action, and the plunger having means to engage the sleeve so as to cause the sleeve to move over center and to move relatively to the plunger in so doing.

Another object of the invention is to provide an arrangement as in the foregoing object wherein the sleeve has associated therewith a contact actuating member operable to perform a switching function.

Numerous additional objects and advantages of the invention will be observed from the following detailed description and annexed drawings wherein.

FIGURE 1 is a cross-sectional view of the switch at enlarged scale.

FIGURE 2 is a cross-sectional view of the invention at enlarged scale taken along the line 22 of FIGURE 1.

FIGURE 3 is a bottom view of the device of FIG- URE 1.

FIGURE 4 is a detail view of the plunger sleeve and contact actuating member.

Referring now to FIGURE 1 of the drawings the device comprises a cylinder casing 10 having a flanged top plug 11 and a similar flanged bottom plug 12. The top and bottom plugs may be attached to the casing 16 by means of screws or the like.

The top lug 11 has a central screw threaded bushing 13 and, as shown, the bushing carries a lock washer 14 and hexagonal nut 15 for attaching the switch body to an opening or aperture of appropriate size. The top plug 11 has an internal downwardly extending skirt 19 the pur pose of which will be described presently.

The bottom plug 12 has an upstanding central cylindrical guide 20 having diametrically opposed vertical slots 21, the purpose of the member 20 being to guide the operating plunger stem as will be described presently.

Upstanding from the bottom plug 12 within the casing 10 are brackets 22 and 22a which have horizontal portions riveted to the bottom plug 12, the purpose of these brackets being to support and carry switch blades as will be described (see FIGURE 2). The bracket 22 supports two switch blades 23 and 24 by means of screws 25. On the outside of the brackets 23 and 24 are insulative spacer member 26 and 27 and between the two switch blades 23 and 24 are two contactor strips 29 and 30 having an insulator spacer 31 between them. Each of the contact strips 29 and 30 is connected by a narrow metal strip to a terminal post as will be described, this strip connection for the strip 30 being shown at 32 in FIG- URE 2.

The switch blade 23 carries a contact 35 and the switch blade 24 carries a cooperating contact 36. Switch blade 24 has an inwardly crimped angular portion 37 engaging an actuation member as will be described. The switch mechanism is substantially symmetrical about a central axis and on the opposite side of the casing of the switch mechanism just described is an identical switch mechanism identified by similar numerals and by the character a.

Upstanding from the bottom plug 12 are four terminal posts in the form of bolts 40, 41, 42 and 43 (see FIGURE 3). The two terminal posts on each side of the casing 10 are connected to the respective switch blades on that side of the casing by connector strips as those shown at 32 and 3211. Each terminal post carries an insulator bushing within casing 10 as shown.

Underneath the bottom plug 12 the terminal posts through 43 carry contact brackets or clips as shown for the attachment of wires.

The operating mechanism of the switch comprises a reciprocatable plunger mounted in the bushing 13 and the lower end of the plunger forming a guide stem movable in the previously described guide 20. The lower end of the plunger 50 has a transverse pin 51 therein which engages in the vertical slots 21 in the guide 20. Mounted on the plunger 50 is a cylindrical sleeve 53 having a top flange 54 and including a fiat horizontal plate 55 (see FIGURE 4). Movably carried on the sleeve 53, is a contact actuating member 56 in the form of a rectangular block made of composition having an opening therethrough of a size to engage on the sleeve 53. Attached to opposite sides of the block 56 are plates 57 and 3 57a which are attached by screws as shown (see FIGURE 2 Each of the plates 57 and 57a has formed therein a groove or notch as may be seen at 58 in FIGURE 1. This notch is relatively shallow and the bottom of the notch is a flat surface of relatively narrow width.

With the parts in the position shown in FIGURE 1 the block 56 is in its upper-most position engaging the downwardly extending skirt 19 of top plug 11. The sleeve 53 is also in its uppermost position with the plate 55 engaging the block 56 with the upper part of sleeve 53 within the skirt 19. With the parts in this position the inwardly crimped portions of blades 24 and 24a engage a fiat surface of the plates 57 and 57a adjacent to but not in the notches 58 and 58a. In this position of the parts the switch blades 24 and 24a are urged outwardly so that the contacts 35 and 36 are engaged and the contacts 35a and 36a are engaged.

Upstanding from the bottom plug 12 are metal strips 60 and 60a which are angularly crimped at their upper ends and which form spring detents cooperating with the plate 55 of block 56. These members are attached to the plug 12 by rivets as shown and at their upper upper ends, as shown, they have an angular crimp as shown at 61 and 61a and an angular crimp 62 and 62a. The crimps 61 and 61a resiliently engage the ends of the plate 55 as shown and the crimps 62 and 62a form the deadcenter position of an over-center snap mechanism formed by motion of sleeve 53 relative to the spring members 60 and 60a.

The plunger 50 has a transverse pin 63 adapted to engage the flange 54 on the sleeve 53. Plunger 50 has another transverse pin 64 adapted to engage a washer 65 and disposed between this washer 65 and the top of guide 20 is a biasing spring 66 which resists downward motion of the plunger 50. The upper part of the plunger 50 has two transverse openings 69 adapted to register with similar transverse openings 70 in the bushing 13 when the plunger is pushed down. An arming wire or pin may be inserted through the aligned openings to hold the plunger in position as will be described.

With the parts in the position, as shown in the FIG- URES 1 and 2 the contacts of both pairs of switches are closed and the plunger is in its upward or retracted position.

To operate the switch mechanism to open position of the contacts, plunger 50 is depressed with its lower end moving downwardly in the guide 20. As the plunger 50 moves downwardly, duringits pre-travel movement the pin 63 engages the flange 54 at the top of sleeve 53; sleeve 53 then begins its downward movement and by its frictional engagement with the crimped ends of members 60 and 60a these members are spread further apart. During this movement the block 56 remains in the position shown in FIGURE 1 being restrained by its frictional engagement with blades 37 and 37a. When the sleeve 53 reaches the point where plate 55 passes over the crimps 62 and 62a which is a dead-center position, the sleeve 53 is then snapped downwardly to the extremity of crimps 62 and 62a. During this snap movement the flange 54 at the upper end of the sleeve 53 engages the top of block 56 and snaps this block downward with it with the result that the switch blades 37 and 37a snap into the notches 58 and 58a in the plates 57 and 57a thereby opening the switch contacts with a snap action. At this time the biasing spring 66 will be compressed and as will be observed the plunger 50 may be depressed a small further distance after the contacts 35 and 36 have opened since during the snap movement the sleeve 53 will have been snapped down away from the pin 63 in plunger 50. Thus the plunger 50 can be depressed until openings 69 align with the openings 70 and an arming wire 01- pin can then be inserted into the aligned openings to restrain plunger 50 in its depressed position with the contacts open. When the arming wire or pin is then withdrawn from the aligned openings at the time the bomb or missile, for example, is dropped from an airplane the biasing spring 66 will urge the plunger 50 upwardly and the snap mechanism will operate in the reverse manner. That is, the pin 64 will engage the plate 55 of sleeve 53 and this plate will be snapped upwardly into the position shown in FIGURE 1. In so doing as it passes dead-center position it will engage or pick up the block 56 and the block will be snapped upwardly into closed position of the contacts as shown in FIGURE 2. The plunger 50 will return to its position as shown in FIGURE 1.

From the foregoing those skilled in the art will observe that I have provided a very elfective snap acting switch mechanism wherein definite amounts of pre-travel and over-travel of the switch actuating member are pro vided. The actuating plunger engages with the snap acting mechanism and the snap acting mechanism engages or picks up the switch actuating member near dead-center position in such a manner that a snap motion is imparted to the actuator member. As will be seen there are no positive connections between operating plunger and the contacts to be actuated with the result that the danger of binding or jamming in such connections is eliminated.

The foregoing disclosure is representative of a preferred form of the invention and it is intended that such modifications, alternatives and variations as may be adapted by those skilled in the art shall come within the scope of the claims appended hereto.

I claim:

1. In a switch device of the character described, the combination of a housing including a skirtlike portion to limit movement of a sleeve means, a plunger adjacent and extending along said skirtlike portion having a plurality of spaced projections extending laterally therefrom, a sleeve member on said plunger intermediate the plunger projections and slidable along the plunger intermediate said projections having shoulders extending laterally therefrom at spaced intervals, sleeve means encircling and slidable along said sleeve member intermediate said shoulders having a surface in alignment with and movable into and out of contact with an end of said skirtlike portion, said sleeve means including a recess to receive a portion of an adjacent circuit-closing member to facilitate movement of said circuit-closing member toward the sleeve means and including a raised portion to facilitate movement of the circuit-closing member away from the sleeve means, spring means to urge the plunger in one direction and said sleeve means toward said end of the skirtlike portion, a resilient circuit-closing member adjacent said sleeve means having a portion projecting toward said sleeve means and normally under stress urging it toward and into contact with said sleeve means, and a resilient retaining member adjacent said sleeve member and normally under stress urging it toward the sleeve member having a recessed portion to receive one of said sleeve member shoulders and resiliently retain the sleeve member and sleeve means with said surface of the sleeve means in con tact with said end of the skirt like housing portion and having an inclined portion spaced from its said recessed portion and disposed generally toward said plunger to urge said sleeve member along the plunger independently of said sleeve means.

2. A switch device as claimed in claim 1, in which said resilient circuit-closing member and said resilient retaining member are angularly spaced from each other about said plunger.

3. A switch device as claimed in claim 1, in which there is provided a pair of said resilient circuit-closing members and a pair of said resilient retaining members and each of said resilient members is angularly spaced from the others about the plunger.

4. A switch device as claimed in claim 1, in which said housing has an extension projecting therefrom and disposed alongside said plunger, said extension has an aper- 3,219,77 6 5 6 ture therethrough, and said plunger has an aperture there- References Cited by the Examiner in registerable with said aperture of the extension to facili- UNITED STATES PATENTS tate insertion of means such as a pin member to maintain said housing and plunger in definite relationship. 2; g 200 77 5. A switch device as claimed in claim 1, in which said 5 04'553 3 1 6 02 7 2 projecting portion of the resilient circuit-closing member ,4 7/1 6 W3 35 1 and said raised port on of the sleeve means are positloned KATHLEEN H. CLAFFY, Primary Examiner so that the pro ecting portion rests against said raised portion when the sleeve means is in contact with said end JAMES L BREWRINK, NORMAN S, of the skirtlike portion. 10 Exammers. 

1. IN A SWITCH DEVICE OF THE CHARACTER DESCRIBED, THE COMBINATION OF A HOUSING INCLUDING A SKIRTLIKE PORTION TO LIMIT MOVEMENT OF A SLEEVE MEANS, A PLUNGER ADJACENT ANND EXTENDING ALONG SAID SKIRTLIKE PORTION HAVING A PLURALITY OF SPACED PROJECTIONS EXTENDING LATERALLY THEREFROM, A SLEEVE MEMBER ON SAID PLUNGER INTERMEDIATE THE PLUNGER PROJECTIONS AND SLIDABLE ALONG THE PLUNGER INTERMEDIATE SAID PROJECTIONS HAVING SHOULDERS EXTENDING LATERALLY THEREFROM AT SPACED INTERVALS, SLEEVE MEANS ENCIRCLING AND SLIDABLE ALONG SAID SLEEVE MEMBER INTERMEDIATE SAID SHOULDERS HAVING A SURFACE IN ALIGNMENT WITH AND MOVABLE INTO AND OUT OF CONTACT WITH AN END OF SAID SKIRTLIKE PORTION, SAID SLEEVE MEANS INCLUDING A RECESS TO RECEIVE A PORTION OF AN ADJACENT CIRCUIT-CLOSING MEMBER TO FACILITATE MOVEMENT OF SAID CIRCUIT-CLOSING MEMBER TOWARD THE SLEEVE MEANS AND INCLUDING A RAISED PORTION OF FACILITATE MOVEMENT OF THE CIRCUIT-CLOSING MEMBER AWAY FROM THE SLEEVE MEANS, SPRING MEANS TO URGE THE PLUNGER IN ONE DIRECTION AND SAID SLEEVE MEANS TOWARD SAID END OF THE SKIRTLIKE PORTION, A RESILIENT CIRCUIT-CLOSING MEMBER ADJACENT SAID SLEEVE MEANS HAVING A PORTION PROJECTING TOWARD SAID SLEEVE MEANS AND NORMALLY UNDER STRESS URGING IT TOWARD AND INTO CONTACT WITH SAID SLEEVE MEANS, AND A RESILIENT RETAINING MEMBER ADJACENT SAID SLEEVE MEMBER AND NORMALLY UNDER STRESS URGING IT TOWARD THE SLEEVE MEMBER HAVING A RECESSED PORTION TO RECEIVE ONE OF SAID SLEEVE MEMBER SHOULDERS AND RESILIENTLY RETAIN THE SLEEVE MEMBER AND SLEEVE MEANS WITH SAID SURFACE OF THE SLEEVE MEANS IN CONTACT WITH SAID END OF THE SKIRT LIKE HOUSING PORTION AND HAVING AN INCLINED PORTION SPACED FROM ITS SAID RECESSED PORTION AND DISPOSED GENERALLY TOWARD SAID PLUNGER TO URGE SAID SLEEVE MEMBER ALONG THE PLUNGER INDEPENDENTLY OF SAID SLEEVE MEANS. 